Friction stir welding (FSW) is a technique used to weld metal by generating friction at an interface between the welded components, typically with a rotating spindle. This technique has been used in the aerospace industry to weld large components, for example, rocket fuel tanks. While conventional friction stir welding techniques have proven successful, there is a continual need in the industry to improve the efficiency and reduce the cost associated with purchasing and operating these high-value devices.